Shadows are odd beings found in the Endworld. It is believed that they were designed by the Golems to prevent people from freeing Kax-Teh, as their limp bodies are seen later and as Deadra calls them "dead", Kax-Teh refers to them as "broken", as they no longer served any purpose.
There are two variations of the Shadows: one with a head that is cut up in a spiral and another with a bloated shoulder and a hole in its abdomen. Both of these types are identical to eachother in combat, and both are colored a dark black and have glowing eyes (although the first variation lacks eyeholes).
With an unlit torch, a Shadow can be killed in three melee attacks, but you will most likely be swarmed if you attempt to go about only attacking like this. A lit torch can kill in either one or two melee strikes, depending on if you have thrown a fireball. Fireballs are instant-kills against Shadows, so keep this in mind when they are throwing fireballs at you to catch them and throw them back.
In the temple in which Golem is found, you must defend candles from being blown out by the Shadows as they light up in order to progress. The easiest strategy is to defend a single candle until it is lit, and then move onto the next and repeat the process.